JPH06272384A - Anchoring structure for tension material - Google Patents

Abstract

PURPOSE:To make it possible to clamp a tension material definitely and provide a rust proof effect on a satisfactory extent. CONSTITUTION:The end of a tension material 10 that forms a resin-made film 12 over the whole length of a strand 11, is inserted into a bearing plate 20 and a male cone 30 while a wedge 10 having a plurality of projected stripes on an inner surface of a central groove 41 is inserted into the male cone 30. The round-shaped tipes of the stripes of the wedge 40 is forcibly penetrated through a film 11 and driven into the front surface of the PC strand and clamped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension member fixing structure for fixing tension materials such as super-strength fiber bundles and PC steel materials.

[0002]

2. Description of the Related Art When fixing the end of an unbonded PC strand, of the sheath covering the PC strand, the sheath in the fixing portion is peeled off, and the grease applied to the exposed surface of the PC strand is wiped off. The fixing is performed by using a known fixing tool (pressure bearing plate, wedge, female cone, etc.).

[0003]

Problems to be Solved by the Invention The conventional PC described above
The strand fixing technology has the following problems.

<A> If the gripping force of the wedge for gripping the PC strands is insufficient immediately after the tension, the tension force introduced will be halved. Therefore, it is necessary to introduce tension in anticipation of the decrease, and it is pointed out that the construction is uneconomical.

<B> Even if the wedge grips the rust-proof coated PC strand, the ridges of the wedge are not rust-proof coated, so if the ridges corrode, they cannot be completely gripped.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a fixing structure for a tension member which can surely grip the tension member and has a complete rust preventive effect. Especially.

[0007]

That is, the present invention is a PC
A resin coating is formed over the entire length of the strand, and the end of the tension material with a resin sheath surrounding it is inserted into the pressure plate, and the fixing end of the tension material protruding from the pressure plate to the outside is inserted. A wedge having a plurality of ridges with rust-proof coating on the inner surface of the central groove is inserted into the female cone to be inserted into the female cone to be supported by the bearing plate, and the fixing end portion of the tension member is gripped, and the ridge of the wedge is Is penetrated into the surface layer of the PC strand by penetrating the film of the tension material, and the tension material is fixed by introducing tension force to the tension material in a state where the texture of the protruding end of the wedge and the texture of the PC strand are pressed. It is a fixing structure.

[0008]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

<B> Overall Configuration (FIG. 1) FIG. 1 shows an embodiment of the present invention. The tension member 10 to be fixed is configured by covering the resin strand 12 over the entire length of the PC strand 11 and further coating the resin sheath 13 on the sheath 12. The sheath 13 is externally slidably mounted on the coating 12, and the sheath 13 and the coating 12 form an unbonded structure. Only the coating 12 is exposed in the tension fixing portion of the tension member 10. The tension material 10 is
The pressure bearing plate 20 and the female cone 30 are inserted, and the wedge 40 is vertically divided and gripped. The pressure bearing plate 20, the female cone 30 and the wedge 40 are all covered with a rust preventive coating layer 50 on their entire surfaces.

<B> Wedge In the present invention, the following improvements were made in order to enhance the gripping force of the tension member. That is, a large number of ridges 42 are formed along the circumferential direction on the inner surface of the central groove 41 having a semicircular cross section of the wedge 40. As shown in FIG. 2, the protruding length of the ridge 42 is set to a length that allows the PC strand 11 to be gripped by penetrating the coating 12. The rust preventive coating layer 50 that covers the surface of the ridge 42 is formed to have a thickness of 200 μm or less. Further, since stress concentrates on the ridges 42, the ridges 4
Heat treatment is applied as necessary so that 2 does not break.

[0011]

Next, a method of fixing the tendons will be described.

<A> Setting of fixing device As shown in FIG. 1, the tension member 10 is arranged on a prestressing target (concrete structure) not shown, and the fixing portion of the tension member covered with the coating 12 is a pressure plate. 20 and female cone 30. Next, the wedge 40 is mounted in the female cone 30, and the tension member 10 is lightly gripped by the wedge 40. At this time, since the tension force is not introduced into the tension member 10, the wedge 40 only abuts the coating film 12 of the tension member 10.

<B> Tension When a tension force is applied to the tension member 10, the wedge 40 moves to the female cone 3.
The gripping force of the wedge 40, which is pulled into 0 and grips the tension member 10, gradually increases. As a result, as shown in FIG. 2, the ridge 42 of the wedge 40 pierces the coating 12 and further digs into the surface layer of the PC strand 11. The ridge 42 of the wedge 40
Is covered with an anticorrosion coating layer 50.
Since 0 is thinly formed, the outer state of the ridge 42, particularly the outer state of the tip of the ridge 42 is not affected by the coating of the anticorrosion coating layer 50. Therefore, the ridges 42 can easily break through the coating 12 and penetrate into the surface layer of the PC strand 11. Also,
As shown in FIG. 3, since a strong pressing force is applied to the tip of the ridge 42 when it bites, the rust preventive coating layer 50 on the tip of the ridge 42 is applied.
Peels off. Therefore, the ridges 42 hold the PC strands 11 in a state where the texture of the ridges 42 and the texture of the PC strands 11 are in pressure contact with each other. Therefore, the tip of the ridge 42 is not affected by the rust-preventive coating layer 50 coated on the surface thereof, and is reliably displaced from the PC strand 11 without being displaced from the PC strand 11.
1 can be gripped. Depending on the setting of the thickness of the rust-preventing coating layer 50 covering the ridges 42, the rust-preventing coating layer 50 may be thin between the background of the ridges 42 and the background of the PC strand 11.
There is also a case of leaving and holding.

<C> Rust prevention The rust prevention during fixing of the tension material 10 will be described. FIG. 4 is a sectional view of the tendon 10 held by the wedge 40. Tension material 1
A gap 60 is formed between the coating 12 of 0 and the inner peripheral surface of the wedge 40. For this reason, rainwater and the like enter through the gap 60,
It enters into the void 70 generated in the valley portion between the protrusions 42 shown in FIG. However, the ridges 42 of the wedge 40 are rust-preventive coating layers 50.
As it is covered with, it will not be corroded by rainwater. Further, even if the tip of the ridge 42 is bited into the PC strand 11, the valley portion between the ridges 42 does not corrode,
Corrosion does not erode from the valley portion to the tip, and further does not reach the PC strand 11.

[0015]

[Embodiment 2] In the above-mentioned embodiment, the case where the tension member 10 is the PC strand has been described, but the fixing means of the present invention can be applied to a super-strength fiber bundle such as carbon fiber or aramid fiber. While super-strength fiber bundles have excellent tensile strength,
The coating 12 and the sheath 13 are coated around the super-strength fiber bundle with a known material that is weak against bending and shearing, as in the above-described embodiment. In the present embodiment, if the tips of the protrusions of the wedge 40 are formed to be round, there is an advantage that the super-strength fiber bundle that is easily broken can be fixed without breaking.

[0016]

Since the present invention is as described above, the following effects can be obtained.

<A> Since the thin rustproof coating layer is formed on the surface of the wedge, the shape of the conventional ridge can be maintained and the ridge does not impair the gripping force. For this reason, the protrusions of the wedge can be bitten into the surface layer of the tension member to be firmly gripped, and the tension member can be effectively prevented from shifting.

<B> Since the ridges of the wedge are rust-proof coated, even if rainwater or the like enters the wedge, it does not corrode. Therefore, a great anti-corrosion effect can be obtained.

<C> Strands, which are well-known materials such as PC strands and super-strength fiber bundles, can be applied to the target, and the versatility is wide.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment according to the present invention.

FIG. 2 is a partially enlarged view of a wedge and a tension member during fixing.

FIG. 3 is an enlarged view of III in FIG.

FIG. 4 is a cross-sectional view of the wedge and the tension member during fixing.

Claims (1)

[Claims] 1. A resin coating film is formed over the entire length of the PC strand, and the end of a tension material having a resin sheath is inserted around the coating film through a bearing plate, and the tension is projected from the bearing plate to the outside. Insert the fixing end of the material into the female cone that is supported by the bearing plate, and insert a wedge with multiple ridges with rust-proof coating on the inner surface of the central groove into the female cone to grasp the fixing end of the tension material. , The wedge ridge is penetrated into the surface layer of the PC strand by penetrating the coating of the tension material, and the tension force is introduced to the tension material in a state where the texture of the wedge ridge tip and the PC strand texture are pressed. A tense material fixing structure.